Method for coloring cellulose textile fibers with dyestuffs containing pendant thiosulfate groups



United States Patent O METHOD FOR COLORING CELLULOSE TEXTILE FIBERS WITHDYESTUFFS CONTAINING PEND- ANT THIOSULFATE GROUPS Charles D. Weston,Charlotte, and William S. Gritfith,

Mount Holly, N.C., assignors to Martin-Marietta Corporation, acorporation of Maryland No Drawing. Filed May 28, 1965, Ser. No. 459,933

2 Claims. (Cl. 8-542) ABSTRACT OF THE DISCLOSURE A method for coloringtextile fibers comprising the steps of applying an aqueous compositioncomprising water and dye having per dye molecule at least one pendantthiosulfate group selected from the group consisting of 4SO Na, SSO Kand SSO NH to textile. fibers selected from the group consisting ofcotton, regenerated cellulose, polyamide and polyacrylic; applying tothe fibers an aqueous solution comprising Na S and washing the fiberswith water.

The present invention relates to a method for coloring textile fibers.

The method of the present invention is particularly characterized inbeing a method for coloring textile fibers comprising the steps ofapplying an aqueous composition comprising water and dye having per dyemolecule at least one pendant thiosulfate group selected from the groupconsisting of SSO Na, -SSO K and SSO NH to textile fibers selected fromthe group consisting of cotton, regenerated cellulose, polyamide andpotlyacrylie; applying to the fibers an aqueous solution cornpnising NaS and Washing the fibers with Water.

At the time of initial contact of the dye with the Na S solution, theunfixed dye Will be on the fiber and in the thiosulfate form, e.g. eachdye molecule will have at least one pendant SSO Na, SSO K or SSO NHgroup per molecule of dye.

It has been suggested in the prior art that sodium sulfide or sodiumcyanide may be used for fixing azo, anthraquinone, vat, dioxazine andmetal phthalocyanine dyes having thiosulfuric acid groups ontocellulosic fibers.

These prior art processes have a number of disadvantages andlimitations, some of which follow.

Handling sodium cyanide and the resulting effluent involves problems ofextreme toxicity to humans and fish. Accordingly, it is altogether toodangerous a chemical for practical commercial use in a textile finishingplant.

Sodium sulfide presents a number of problems when used according to theabove prior art method. For example, it must be used in combination withheat to effect fixation; or, when used at room temperature it musteither be used in high concentrations or remain in contact with the dyefor 10-60 minutes to effect fixation. Sodium sulfide affects unfavorablythe softness and feel (hand) of cellulosic fibers and especially that ofregenerated cellulose, and particularly so when used in combination withheat, or in high concentration, or when permitted to remain in contactwith the cellulosics over a relatively long period of time. Regeneratedcellulose swells n contact with strong Na S solutions, thereby requiringrepeated after-washing, and also causing stickness in the unwinding ofyarn from bobbins. Moreover, sodium sulfide is strongly alkaline andprecipitates insolubles from water, especially from hard water, andthese insolubles interfere with dyeing procedures and require additionalsoap for their removal in washing processes.

Some azo dyes are particularly sensitive to sodium sulfide, in that thecolor value of the azo groups is destroyed and color yield iscorrespondingly lowered when sodium sulfide is used, and particularly sowhen the sodium sulfide is at high concentration, or in the presence ofheat, and the longer the azo dye remains in contact with sodium sulfidethe more color value is lost.

There are two distinct types of azo dyes having pendant thiosulfategroups, i.e. (1) those in which the thiosulfate group is attacheddirectly to an aryl nucleus of the dye molecule, and (2) those in whicha bridge member, such as an aliphatic or hydrocarbon radical which maybe substituted and interrupted by hetero groups, is interposed betweenthe thiosulfate group and an aryl nucleus of the dye.

Sodium sulfide presents additional and special problems when used as afixing agent for those azo dyes having a pendant thiosulfate groupattached directly to an aryl nucleus of the dye molecule. The primaryproblem vis color yield.

With many of the azo dyes having at least one pendant thiosulfate groupattached directly to an aryl nucleus of the dye molecule, it isimpossible to obtain high color yield using sodium sulfide as the fixingagent under any conditions, as an inadequate amount of the dye is fixedon the fibers, Moreover, in the fixation of azo dyes having at least onependant thiosulfate group attached directly to an aryl nucleus of thedye molecule, a narrow and specific amount of sodium sulfide must beemployed for each individual dyestufi, otherwise color yield will bereduced. Slight increases or decreases in the amount of sodium sulfideused for fixing any given azo dye of the type in which a pendantthiosulfate group is attached directly to an aryl nucleus of the dyemolecule can influence color yield markedly. This problem is made evenmore difiicult because of very great differences in the amounts ofsodium sulfide required to fix different azo dyes having at least onependant thiosulfate group attached directly to an aryl group of the dyemolecule; for example, one such azo dye may require 12 times as muchsodium sulfide as another such dye to achieve commercially acceptablecolor yield. Obviously, searching for optimum sodium sulfideconcentrations of fixing baths and changing these concentrations forindividual dyes is a time consuming and expensive burden that few dyersdyeing many different colors would care to assume. To obtain a desiredshade it is frequently necessary to mix two or more azo dyes, eachhaving at least one pendant thiosulfate per dye molecule attached to anaryl nucleus of the dye, and in which the amount of sodium sulfiderequired for fixing each dye is markedly different; in such cases, it isimpossible to obtain full color fixation of both dyes with sodiumsulfide.

The above disadvantages and limitations of the prior art have beenovercome by the method of the present invention, and additionaladvantages have been provided as follows.

Na S is much less hazardous and toxic than sodium cyanide.

In contrast to sodium sulfide, there is no necessity for using Na S incombination with heat to achieve dye fixation, and excellent dyefixation is obtained at room temperature; neither is there any necessityfor using the Na S in high concentration nor for the Na S to remain incontact with the dye for any appreciable length of time to achievefixation.

One surprising feature of the present invention is that fixation of thedyestuff may he achieved at room temperature, and at very low Na Sconcentration, and Without having the dye and Na S in contact for morethan 1-30 seconds. Thus, the process of the present invention isparticularly valuable for use with rnodern high speed dyeing equipment,such as continuous padding ranges. Also, with Na S the fixation isachieved at a lower degree of alkalinity than with sodium sulfide, whichresults in a softer and improved hand of cellulosic fibers, as well asless precipitation of insolubles from water.

Surprisingly, azo dyes having a pendant thiosulfate group attacheddirectly to an aryl group of the dye molecule may be fixed with abouttwo-thirds less weight of Na S than Na s.

The fact that fixation may be achieved at room temperature without anynecessity for high Na S concentration or prolonged contact between thepolysulfide and azo dyes results in less loss of color value of thesensitive azo groups and improved color yield, and in some cases inimproved brightness of shade, in comparison with sodium sulfide.

Improvement in color yield is particularly noticeable in the dyeing ofazo dyes having at least one pendant thiosulfate group attached directlyto an aryl group of the dye molecule. With many of these dyes, coloryield is 20%100% higher when Na S is used than when the optimum sodiumsulfide concentration is used.

Another surprising and very advantageous feature of the presentinvention is that the optimum concentration of Na S for fixing azo dyeshaving at least one pendant thiosulfate group attached directly to anaryl nucleus of the dyestufi and obtaining high color yield extends overa very much wider range than does sodium sulfide, and thus color yieldis not adversely affected by slight variations in Na S concentration, ascontrasted to sodium sulfide. Moreover, there is only a small differencebetween optimum Na S concentration for fixing one azo dye of theforegoing type and another, quite unlike sodium sulfide. Thus, standardfixing solutions of Na S may be utilized in textile finishing plantswithout the necessity for changing concentrations every time a difierentdye is utilized. Also, better color yield can be obtained in dyeingmixtures of certain azo dyes with Na S than with Na s.

Finally, the system is very economical as Na S costs less than Na s, andless Na S is required than Na S; and soap, time and heat are saved.

A more detailed description of the process of the present inventionfollows:

The present process may be used in dyeing or printing textile fibersselected from the group consisting of cotton, regenerated cellulose,polyamide and polyacrylic. The textile fibers may be in any desiredform, such as fabric, yarn, ball warps, non-woven fabric, raw stock,etc.

Examples of dyes which may be fixed according to the method of thepresent invention include azo, sulfur, phthalocyanine, 'metalphthalocyanine, perylene, dioxazine, anthraquinone, vat anddibenzanthrone dyes, said dyes being further characterized in having atleast one pendant thiosulfate group selected from the group consistingof SSO Na, SSO K and SSO NH per molecule of dye.

The dye stuff may be applied to the fibers in any desired manner, suchas by jig, pad, beck, printing roller, etc. The amount of dye employedwill depend upon the depth of shade desired.

In addition to dye and water, the dye composition may optionally containconventional additives, such as inorganic electrolytes to increaseadsorption of the dye onto the fiber, leveling agents such as sodiumalginate, penetrating assistants such as anionic and non-ionic surfaceactive agents, alkalies, urea, thiourea, etc., and in the case ofprinting pastes conventional gums, thickeners, emulsifiers, etc.

Following application of the dyestuff, the fibers may optionally bebatched for a period of time at ambient temperature or in a closedchamber controlled for humidity and temperature, steamed or dried tofacilitate penetration of the dyestuff into the fibers. However, thefibers may be taken directly from the dye application to the Na Ssolution.

As used herein, the term Na S refers to a sodium polysulfide or tomixtures of sodium polysulfides, e.g. to disodium disulfide, or disodiumtrisulfide, or disodium tetrasulfide, or to mixtures of any two or threeof these polysulfides. In the case of mixtures, the 2-4 subscript of theS atom would not necessarily be a whole number. Sodium polysulfides arewell known, and are prepared by adding flowers of sulfur to a hotaqueous solution of sodium sulfide.

Sulfur is precipitated from highly concentratedstock solutions of sodiumtetrasulfide on extended exposure to the air, and this may be preventedby adding 5% by weight of Carbitol t0 the concentrated stock solutions,which stock solutions may be used subsequently in preparing the fixingsolutions.

The fibers, having thereon the unfixed dyestulT in thiosulfate saltform, are then contacted with the aqueous Na S fixing solution, such asby immersing the fibers in the fixing solution. The fibers may be wet ordry at the time of contact with the fixing solution.

The fixing solution comprises an aqueous solution of Na S The amount ofNa S utilized is basedupon the amount of dye which is to be fixed; about0.07-0.64 gm. Na S and preferably about 0.214 gm. Na S may be applied tothe fibers for each gram of dye to be fixed. The fixing solution mayalso optionally comprise a simple water soluble inorganic electrolyte,such as NaCl, to deter those dyes which tend to bleed into the fixingsolution from so doing. About 25-300 gm. NaCl per liter of fixingsolution is suitable for this purpose. The Na S is applied as an aqueoussolution to the fibers, and may be applied by the pad-nip method,spraying, immersing the fibers in the solution, or any other convenientmethod. A convenient and illustrative method is to pass the fibershaving the unfixed dye thereon through a pad box containing about 1-10gm. Na S per liter of fixing solution for each percent by weight of thedye upon the fibers, and squeezing the fibers between rubber coatedpressure rollers to permit 60% Wet pick up of fixing solution based onfabric weight. Fixation of the dye is very rapid, and in many cases maybe regarded as instantaneous. In most cases, fixation -will be completewhen the dye and Na S have been in contact about 1-30 seconds.

After contact with the Na S the fibers are washed with water, which maybe at room temperature. The water serves to remove polysulfide saltresidues and other water soluble residues from the fibers. If desired,the fibers may optionally be passed through air, steam or brine prior towashing.

Following washing, the fibers may be scoured and dried in conventionalmanner.

Dyeings and prints having excellent color yield and wash fastnessproperties result from the above process.

The following examples are illustrative of the process of the presentinvention. All parts are by weight unless otherwise specified.

Example 1 Onto mercerized cotton 'fabric weighing 112 gms. per squareyard is padded a dye composition consisting of per liter of water at F.;the fabric is squeezed to ing of 6.05 gm. Na S and 200 gm. NaCl perliter at room temperature; the fabric is squeezed to permit 60% wet pickup based on fabric weight (whereby the fabric has thereon 0.214 gm. Na Sfor each gm. of dye. The

lated as dry solids) per gm. of fabric; the fabric is pre-dried in openwidth with infra-red units to about moisture content and then dried tosubstantial dryness in open width on a housed tenter frame heated fabricis Washed with water at room temperature and 5 to 350 F.; the fabric issteamed for 2 minutes at 230 dried. F. in an air-free steamer; paddedthrough a solution A bright yellow dyeing with excellent wash fastnessconsisting of 4.537 gm. of the polysulfide shown in colresults. umn 3and 200 gm. NaCl per liter of water at room *If desired, the NH; or Ksalt of the above dye may be temperature; squeezed so as to have pickedup the numsubstituted for the dye used in this example. 10 her of gm.shown in the fourth column of the polysulfide The color yield in theabove dyeing is at least twice shown in the third column (calculated asdry solids) for as great as obtainable by using Na s as the fixingagent. each gm. of dye on the fibers, passed through pad boxes E 2 6equipped with exit nip rollers and containing water at Xamples roomtemperature for seconds, and then soaped, rinsed In the examples givenin the following table, there is 15 with w er. n dried- W fast dyeings0f the color \padded onto cotton, viscose rayon, polyamide or polyshownin the fift-h column and having good color yield acrylic fabric anaqueous dye composition consisting of re u tgm. of the dye indicated inthe second column It will be understood that the Na atoms of the pendantper liter of water at 140 F., whereafter the fabric is thiosulfategroups of the dyes shown in the second colsqueezed so as to have pickedup 0.015 gm. dye (calcu- 20 umn may be substituted by K or NH Ex. DyePoly- Gms. Color No. sulfide 2 Dye of Example 1 NaiSz 0.20 Yellow. 3. do1 NazS; 0.27 Do. 4. -..do Na2S3.5 0.15 Do. 5 1. Sodium salt of dyeobtained by coupling equimolar amounts of diazotizedB-amino-benzylthiosulfuric acid and 3- N azSz 0.30 Scarlet.

(2,3-hydroxynaphthoylamino)benzylthiosuliuric acid. 6 --do N82S3 0.21DO. 7. do NazS4 0.15 Do. 8 Sodium salt of dye obtained by coupling moleof diazotized sodium S-4-aminophenylthiosulfate andmole OfSamino- NazSz0.30 Black.

2-xtliaphthol, and coupling equimolar amounts of result and diazotizedsodium S-4-aminophenylthiosulfate. D 9 0 0.25 o. 0.15 Do. 0.20 Green.0.15 Do. 0.80 Do. 0.17 Turquolse Nags; 0.22 Do. 16 ..dO Nazsq 0. D0. 17Sodium salt of dye obtained by condensing mole of copper phthalocyaninetrisulfonyl chloride and 3 moles sodium N azSz 0. 15 D0.

S-4aminophenylthiosulfate. 18 ..do Nags; 0.23 Do. 10 ..dO N82S4 0.28 D0.20. Sodium salt of dye obtained by condensing 1 mole of nickelphthalocyanine trisulfonyl chloride with 3 moles Nazsg 0.24 Do.

sodium S-(2-aminoethyl)thiosulfate. 21 ..do Nazsa 0.30 Do. 22 ..do Nags;0.15 Do.

23 SOZNHCHflCHZSSOQNB O O Na s: 0.15 Red.

O O NaOgSSCIhCHgN SO;

24 Same as Ex. 23 above. Na sa 0.26 Red. 25. -dO Nazs4 0.22 Red. 26... zj NagSi 0.29 Blue.

H5C2N V 01o1 somncrnomssomah 0. 24 Do. 0.15 Do.

Ex. Dye Poly- Gms. Color No. sulfide 30- Sameas Ex. 29 above Nags; 0.30Do. 7 31 d Na2S4 O. Do. 32.--" Sodium salt of dye obtained by reactingmole of dlsulionyl chloride of isodlbenzanthrone and 2 moles sodium N9482 0.16 D0.

S-(2-aminoethyl)thiosuliate. 33 d0 Nags; 0. 19 Do. 34 do NmSr 0.30 Do.

35.-." Nags 0. 22 Orange.

N=N-- S 0 21110 H; N=N- -S O 1N C H;

CH3 OH: on, on,

SSOSNQ SSO Na Vivi O O Y i 36. Same as Ex. 35 above Nags 0.20 Do. 37..do N8zS4 0.18 Do. as..." C0NHOH;4CH SSO3Na N528, 0.15 Yellow.

H I N=N ion SOgNH-CHgCHz-SSO;Na

l SOB-NHCH2CH SSO:Na

s9 Same as Ex. 38 above Nags 0.30 Do. 40 .-d0 Nags; 0. 20 DO.

41..- SOzN(CHa)CH2CH2SSO3N8 N825: 0. Red.

1 fion (3H3 ooNH-oomomssoma 42 Same as Ex. 41 above O. 19 Red. 43 d0 0.26 Red. 44... Sodium salt of dye resulting from condensing mol 0.30Blue.

sodium S-(4-arnino-benzy1)thiosuliate.

0 Nags; 0. 24 Do. do N83S4 0.15 Do.

Example 47 Onto cotton fabric is printed a paste consisting of, byweight, 2.5%

Example 4-8 Onto cotton fabric weighing 112 gm./sq. yd. is padded a dyecomposition consisting of 12.5 gm.

per liter of water at F.; the fabric is squeezed to 60% wet pick up soas to retain 0.0075 gm. dye, calculated as solids, per gm. of fabric.The fabric is immersed for 30 seconds in a solution consisting of 0.375gm. Nags4 per liter of Water at a liquor to goods ratio of 10:1, rinsedwith water at room temperature for 5 minutes, soaped, rinsed with Waterand dried, resulting in a bright orange dyeing.

Example 49 N-Q-SSOaNa is padded onto cotton fabric and squeezed so as todeposit 1.5 gm. dye/ 100 gm. cotton. The fabric is dried and paddedthrough a solution consisting of 7.86 gm. Na s, and 200 gm. NaCl perliter of water at room temperature, squeezed to permit 60% wet pick up,rinsed with water, scoured and dried. A bright orange dyeing results.

Nearly twice as much Na s as Na S is required to give somewhat lesscolor yield and less brightness.

Example 50 Onto cotton corduroy fabric is padded a dye compositionconsisting of 10 gm. of the sodium salt of the dye resulting fromcondensing a mole of FESO2C1 L a 10.7 and 2.3 moles sodiumS-4-aminophenylthiosulfate, 7 gm. of the sodium salt of Cl. SolubilizedSulphur Green 2 (C. I. No. 53572), and 15 gm.

GHQ-0:31

per liter of water at 130 F. The fabric is dried, padded through anaqueous solution consisting of 6 gm. Na S and 200 gm. NaCl per liter ofwater at room temperature, squeezed to permit 60% wet pick up, rinsedwith water, soaped, rinsed and dried. A green dyeing results,

Example 51 An aqueous composition containing 25 gm.

OCHa

per liter of water at 120 F. is padded onto cotton fabric and squeezedso that the fabric retains 0.015 gm. dye per gm. of fabric, and thefabric is dried. The fabric is then padded through a solution containing1.9 gm. Na S and Example 52 This example is the same as Example 51above, except that the amount of the Na S per liter is increased from1.9 to 10 gm., and except that the amount of Na S picked up per gm. ofdye is increased from 0.07 to 0.64 gm.

What is claimed is:

1. A method for coloring textile fibers consisting essentially of thesteps of applying an aqueous composition comprising Water and dye havingper dye molecule at least one pendant thiosulfate group selected fromthe group consisting of SSO Na, SSO K and SSO NH to textile fibersselected from the group consisting of cotton and regenerated cellulose;applying to the fibers an aqueous solution comprising Na S so that about0.07- 0.64 gm. Na S are applied to the fibers for each gram of dye onthe fibers; and washing the fibers with water.

2. A method for coloring textile fibers consisting essentially of thesteps of applying to textile fibers selected from the group consistingof cotton and regenerated cellulose, an aqueous composition comprisingwater and dye, said dye being selected from the group consisting of azo,sulfur, phthalocyanine, metal phthalocyanine, perylene, dioxazine,anthraquinone, vat and dibenzanthrone dyes having per dye molecule atleast one pendant thiosulfate group selected from the group consistingof SSO Na, SSO K and SSO NH applying to the fibers an aqueous solutioncomprising Na S so that about 0.07-0.64 grn. Na S are applied to thefibers for each gram of dye on the fibers; and washing the fibers withwater.

References Cited UNITED STATES PATENTS 3,088,790 5/1963 Schultheis et a1854.2 3,225,025 12/ 1965 Jeremias et a1. 8-37 X 3,264,053 8/ 1966Holtzclaw et al. 8-37 X OTHER REFERENCES G. Kaufman: MelliandTextilberichte, November 1963, pp. 1245 and 1246, 8/1213.

K. Venkatataman: The Chemistry of Synthetic Dyes, volume 2, 1952, p.1093, TP913 V4C.3.

NORMAN G. TORCHIN, Primary Examiner.

T. J. HERBERT, JR., Assistant Examiner.

U.S. Cl. X.R. 8--34, 39, 41

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,419,343 December 31, l9

Charles D. Weston et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

line 66, "stickness" should read stickiness should read SSO NH line 56,

Column 9, lines 38 to Column 1, Column 3, line 54, "SSO NH should readdyestuff H "dye stuff" 50, the formula should appear as shown below:

i i Na0 ss-N=N-cn I C=O I NH I CH Signed and sealed this 10th day ofMarch 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JRG

Commissioner of Patents Attesting Officer

